diff --git a/api/db/index.js b/api/db/index.js
index 5c29902f69..f4359c8adf 100644
--- a/api/db/index.js
+++ b/api/db/index.js
@@ -1,8 +1,13 @@
 const mongoose = require('mongoose');
 const { createModels } = require('@librechat/data-schemas');
 const { connectDb } = require('./connect');
-const indexSync = require('./indexSync');
 
+// createModels MUST run before requiring indexSync.
+// indexSync.js captures mongoose.models.Message and mongoose.models.Conversation
+// at module load time. If those models are not registered first, all MeiliSearch
+// sync operations will silently fail on every startup.
 createModels(mongoose);
 
+const indexSync = require('./indexSync');
+
 module.exports = { connectDb, indexSync };
diff --git a/api/db/index.spec.js b/api/db/index.spec.js
new file mode 100644
index 0000000000..e1ebe176dc
--- /dev/null
+++ b/api/db/index.spec.js
@@ -0,0 +1,26 @@
+describe('api/db/index.js', () => {
+  test('createModels is called before indexSync is loaded', () => {
+    jest.resetModules();
+
+    const callOrder = [];
+
+    jest.mock('@librechat/data-schemas', () => ({
+      createModels: jest.fn((m) => {
+        callOrder.push('createModels');
+        m.models.Message = { name: 'Message' };
+        m.models.Conversation = { name: 'Conversation' };
+      }),
+    }));
+
+    jest.mock('./indexSync', () => {
+      callOrder.push('indexSync');
+      return jest.fn();
+    });
+
+    jest.mock('./connect', () => ({ connectDb: jest.fn() }));
+
+    require('./index');
+
+    expect(callOrder).toEqual(['createModels', 'indexSync']);
+  });
+});
diff --git a/api/db/indexSync.js b/api/db/indexSync.js
index 130cde77b8..13059033fb 100644
--- a/api/db/indexSync.js
+++ b/api/db/indexSync.js
@@ -6,9 +6,6 @@ const { isEnabled, FlowStateManager } = require('@librechat/api');
 const { getLogStores } = require('~/cache');
 const { batchResetMeiliFlags } = require('./utils');
 
-const Conversation = mongoose.models.Conversation;
-const Message = mongoose.models.Message;
-
 const searchEnabled = isEnabled(process.env.SEARCH);
 const indexingDisabled = isEnabled(process.env.MEILI_NO_SYNC);
 let currentTimeout = null;
@@ -200,6 +197,14 @@ async function performSync(flowManager, flowId, flowType) {
       return { messagesSync: false, convosSync: false };
     }
 
+    const Message = mongoose.models.Message;
+    const Conversation = mongoose.models.Conversation;
+    if (!Message || !Conversation) {
+      throw new Error(
+        '[indexSync] Models not registered. Ensure createModels() has been called before indexSync.',
+      );
+    }
+
     const client = MeiliSearchClient.getInstance();
 
     const { status } = await client.health();
@@ -349,6 +354,13 @@ async function indexSync() {
       logger.debug('[indexSync] Creating indices...');
       currentTimeout = setTimeout(async () => {
         try {
+          const Message = mongoose.models.Message;
+          const Conversation = mongoose.models.Conversation;
+          if (!Message || !Conversation) {
+            throw new Error(
+              '[indexSync] Models not registered. Ensure createModels() has been called before indexSync.',
+            );
+          }
           await Message.syncWithMeili();
           await Conversation.syncWithMeili();
         } catch (err) {